约束边界和销轴简化对液压支架强度影响

为准确分析液压支架在顶梁扭转加载试验时的强度特性,以ZY6800/08/18D型液压支架为研究对象,采用整机建模的方式,建立了液压支架的三维实体有限元模型.根据液压支架试验的测试结果,选取仿真模型上的测点位置,分析对比顶梁和底座在8种不同的约束边界条件下,液压支架的应力分布情况,同时分析带摩擦的接触边界条件下底座和平台的接触应力分布及接触状态,指出顶梁扭转加载时的载荷不对称导致的底座不完全接触的现象.在不改变顶梁和底座约束边界的条件下,分析4种销轴连接简化方法对液压支架整体应力分布的影响.对比仿真结果与测试结果,分别评估各种边界条件和不同销轴连接简化方法的准确性,以及对仿真效率的影响.结果表明,液压支架的顶梁边界选择固定支撑,底座边界选择与工作台摩擦接触,保留销轴并将销轴与轴孔绑定接触得到的仿真结果最接近试验结果,且有较高的计算效率.研究结果可为液压支架设计过程中准确预估应力分布提供依据和参考.

Effects of constraint boundaries and simplified pin joints on strength of hydraulic support

To accurately analyze the strength characteristics of hydraulic support considering the canopy torsional loading condition, by taking ZY6800/08/18D hydraulic support as the research object, the three-dimensional solid finite element model is established. According to the results of hydraulic support test, selecting the location of measuring points on the simulation model, the stress distributions of the hydraulic support are compared under eight boundary conditions for the canopy and base. In addition, the contact stress and status are analyzed under the frictional contact boundary condition between the base and worktable. It is pointed out that the phenomenon of incomplete contact of the base is caused by the load asymmetry during the canopy torsional loading. The influence of four simplified methods for pin joint on the stress distribution is also analyzed under the constant constraint boundary condition. Finally, the stress distribution obtained from the experiment evaluates the accuracy and efficiency of various boundary and pin joint simplification methods. When the canopy boundary selects fixed support, the base boundary selects friction contact with the working table, and retaining the pin joint and bonding the pin joint to the axle hole, the simulation results are the closest to the test results, and the simulation has high-efficiency. The research results can provide the basis and reference for the accurate estimation of the hydraulic support stress distribution.